612 
NATURE 
| April 26, 1883 
Association. The real question to which Mr. Reynolds’s 
tests point is probably how far theories which rest on the 
hypothesis that elasticity is perfect can properly be 
applied to cases where the breaking point has been nearly 
reached ; and this is a question on which more light is 
very urgently needed, especially with reference to such 
cases as screw-shafts, where fractures, as a matter of 
fact, do very commonly occur. 
The second paper, by Mr. W. Ford Smith, dealt with 
twist drills, milling machines, and other methods for the 
cutting and dressing of metal surfaces, which have been 
introduced within the last few years; and was almost en- 
tirely of a practical character. The third paper, by Mr. 
John Jameson, was on ‘‘ Improvements in the Manufac- 
ture of Coke,” and dealt with a new method, invented by 
the author, for recovering the gas, gas-tar, and ammo- 
niacal liquor, which are separated from coking coal 
during the process of carbonisation. As the paper points 
out, these products are not originally present in the coal. 
There is, for instance, no ammonia in coal; but there 
are combinations containing nitrogen and hydrogen, and 
in almost any process of distillation parts of the evolved 
nitrogen and hydrogen unite, under very obscure condi- 
tions, to form ammonia, which, however, is not stable, 
but readily decomposes in the presence e.g. of oxygen. 
Every process of distillation, in fact (but some much more 
than others), favours the formation of gas on the one hand 
and of condensable hydrocarbons on the other. With 
regard to the former, its value in the neighbourhood of 
coke-ovens is not usually high, and it is a question 
whether it may not best be burnt in the oven itself, to 
furnish the heat required in any case for the distilling 
process ; but the value of tar and ammonia is great, and 
would probably not fall very low, even if the production 
were largely increased. At the same time, as a fuel they 
are not even equal to the same weight of pure carbon. It 
will be seen, therefore, that there is ample room for a 
process which will enable us to separate and utilise these 
by-products, instead of simply using them as fuel, or, 
which is far worse, discharging them unburnt to poison 
the air and destroy vegetation. Mr. Jameson’s method 
of effecting this end is very simple. He takes an ordinary 
“ beehive ” coke-oven, makes it tolerably airtight by letting 
tar soak into the brickwork, and covers the floor wich an 
impervious substance, in which are inserted some large 
bricks or quarls, pierced with holes. Below these is a 
chamber connected with a pipe, which leads, through any 
convenient form of condenser, to a small exhausting 
fan. The oven is now charged and lighted from the 
top, to which alone air is admitted. The heat of com- 
bustion, penetrating downwards, gradually distils the 
pitch and gases out of the coal, and the fan being set to 
work, these products, instead of passing upwards to the 
fire, are sucked downwards through the holes in the floor, 
and afterwards separated, the tar being left in one con- 
denser, the ammoniacal liquor in another, and the gas 
either used at once for steam-raising, &c., or stored in a 
gas-holder till required. 
In the discussion which followed, the advantage of 
saving the waste products was fully admitted, though some 
rather startling estimates of the author (who had assumed 
that 75,000,000/, per annum was practically wasted under 
our present system of coal consumption) were sharply 
criticised. But by the ironmasters who were present it 
was strongly laid down that the first duty of a coke-oven 
was to make good coke—such coke as would give the 
best results in a blast-furnace ; and that to this duty all 
consideration of by-products must give way. It was 
further suggested that pitch was a valuable ingredient in 
coke, and that this pitch was left in it by the present 
system, but withdrawn on the new one. This idea, how- 
ever, seems to be founded on a misapprehension. Mr. 
Jameson and others were able to state positively that the 
coke made by his process could not be distinguished in 
quality from the product of the old beehive oven ; that 
the quantity per ton of coal was the same; and that the 
by-products, though differing very greatly in quantity 
according to the character of the coal, method of con- 
densation, &c., were almost always sufficient to repay, 
within a few months or even weeks, the 10/. or 15/. re- 
quired to adapt an existing oven to the new arrangement. 
If these results are confirmed by more extended trials in 
different localities, the process seems likely, as one 
speaker phrased it, “to take a pretty prominent position 
among the great inventions of the present day.’’ 
CORONERS’ SCIENCE IN CHINA 
HETHER Chinamen are or are not believers in the 
principle that it is better that nine guilty persons 
should escape rather than that one innocent person 
should suffer, they do at all events, by their manner of 
conducting inquests, leave open a wide door for the 
escape of murderers. A deeply-rooted repugnance to 
dissection of the human body and a consequently slight 
acquaintance with anatumy, coupled with an entire ignor- 
ance of the action of poisons, deprive coroners of every 
means of arriving at decisions except those furnished by 
outward symptoms and appearances. From early times, 
however, the importance attaching to human life has 
been recognised by the custom of holding inquests in 
cases of sudden death, and various works have been pub- 
lished embodying all the knowledge available on the sub- 
ject to assist coroners in their duty of investigation. The 
best-known of these was the Se yen duh, or ‘‘ Record of 
the washing away of wrongs,” which was given to the 
world in the thirteenth century, and which, under the 
same title, subsequently received the zwprimatur of the 
officers of the Board of Punishments, who, in the exer- 
cise of their legislative function, issued it as a manual 
for coroners. In this work is expounded the whole 
system of Chinese medical jurisprudence, of which the 
following is a slight sketch 
One of the first directions given to coroners reminds 
one of Mrs. Glasse’s celebrated dictum, and is to the effect 
that before issuing a warrant for an inquest they should 
be quite sure that there really isa corpse. This admonition 
is no less curious than the reason which makes it neces- 
sary. It appears to be not uncommon for unscrupulous 
swindlers to demand inquests on imaginary corpses for 
the purpose of extorting money from the wealthy owners 
of the houses where the bodies are said to be, who, rather 
than fall into the clutches of the law, generally pay the 
sum demanded on condition that all proceedings are 
stayed. But being well assured of the existence of a 
corpse, the coroner should proceed to the spot well pro- 
vided with onions, red pepper, salt, white prunes, and vine- 
gar with the lees. If death has just taken place, he should 
examine the top of the head, back of the ears, throat, and 
any other vital part where a sharp-pointed instrument 
may have been inserted. In case of his failing to find 
any such cause of death, he should interrogate the friends 
and neighbours, and then proceed to examine any 
wounds there may be on any other part of the person. 
An infallible guide to the date of a wound is found in 
the colour of the bone affected. If it is a recent one or 
of a slight nature, the bone will be red, but :f old and 
severe, the bone will be of a dark blue colour. Particular 
care should, however, be taken to ascertain that these 
colours are genuine, and not manufactured to agree with 
the story told by the relatives. A red tint may be given 
to the bone by painting it with an ointment of genuine 
safflover, sapanwood, black plums, and alum, with the 
addition of boiling vinegar. On the other hand, green 
alum or nutgalls, mixed with vinegar, impart a dark blue 
or black hue. These counterfeit colours may, however, 
be distinguished by their want of brightness. Again, not 
uncommonly a fictitious wound is made after death by 
